kernel/git/next/linux-next.git/drivers/thunderbolt/path.c, branch master

thunderbolt: Stop waiting on a path pending bit that never clears

2026-08-31T06:36:34+00:00

__tb_path_deactivate_hop() waits up to 500 ms for a hop's pending bit to read back clear. On an ASMedia ASM4242 host router the host interface adapter latches it once enough frames have gone through the DMA ring and never clears it again: the teardown finds it already set, seconds after the last frame and with the path still up. USB4 v2 table 8-23 has the field read only and zero unless packets belonging to the path are waiting to be dequeued, so the wait is right and this adapter is not. Make the wait a per-adapter length and quirk those routers to zero, which leaves the loop reading the bit exactly once. A hop that does drain still says so on that read, and one that does not answers -ETIMEDOUT without burning the timeout: bringing the interface down takes 6 ms where it took 506. Assisted-by: Claude:claude-opus-5 Signed-off-by: Fan Ye Signed-off-by: Mika Westerberg

thunderbolt: Activate path hops from source to destination

2026-05-20T09:54:34+00:00

Currently, path activation starts from the last hop (destination adapter) and iterates backwards to the first hop (source adapter). This does not follow the order suggested in the USB4 Connection Manager guide and could potentially cause issues with tunnelled protocols. Reverse the activation order to start from the first hop (source adapter) and end at the last hop (destination adapter), as suggested in the Connection Manager guide. Adjust the rollback in the failure path to deactivate from the first hop, since hops are now activated starting at the source. Fix kernel-doc accordingly. Signed-off-by: Gil Fine Signed-off-by: Mika Westerberg

thunderbolt: Avoid reserved fields in path config space for USB4 routers

2026-05-05T11:53:45+00:00

According to USB4 spec, USB4 Connection Manager shall not change value of any fields that are defined as "RsvdZ" or "VD". Specifically fields: Path Credits Allocated, IFC, ISE fields in path config space shall not be written by CM. To handle this, CM shall first read current path config space from the hardware, change only the fields that can be changed, and then write back the path config space. Signed-off-by: Gil Fine Signed-off-by: Mika Westerberg

thunderbolt: Use kzalloc_flex() for struct tb_path allocation

2026-03-23T05:49:43+00:00

Simplifies allocation of struct tb_path by using a flexible array member. Also added __counted_by for extra runtime analysis. Signed-off-by: Rosen Penev Reviewed-by: Kees Cook Signed-off-by: Mika Westerberg

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

thunderbolt: Log path activation failures without WARN backtraces

2026-01-05T11:14:43+00:00

tb_path_activate() currently logs failures with tb_WARN(), which triggers a stack trace. Transient conditions such as lane bonding or Type-C link hiccups can fail path activation briefly, and the resulting backtraces are noisy without aiding diagnosis. Switch to tb_warn() for all path activation failures. The error code is already returned to callers, and the warning still shows the message without the backtrace. Signed-off-by: Chia-Lin Kao (AceLan) Signed-off-by: Mika Westerberg

thunderbolt: Update path.c function documentation

2025-09-17T05:32:59+00:00

Make path.c function documentation compliant with current kernel-doc standards. No functional changes. Signed-off-by: Alan Borzeszkowski Signed-off-by: Mika Westerberg

thunderbolt: Show path name in debug log when path is deactivated

2025-01-03T09:50:08+00:00

Similarly as we do when activating the path. Helps in debugging. Signed-off-by: Mika Westerberg

thunderbolt: Introduce tb_path_deactivate_hop()

2024-01-22T11:21:06+00:00

This function can be used to clear path config space of an adapter. Make it available for other files in this driver. Signed-off-by: Sanath S Signed-off-by: Mika Westerberg